It is known that light passing through a lens causes chromatic aberration of magnification. The chromatic aberration of magnification occurs due to difference in image magnification for each color of light, which is caused because the refractive index of a lens is different according to the wavelength of light. For example, when an image of a white point light source is captured, conditions where the color changes to be iridescent extending in the radiated direction from a position corresponding to the optical axis taken as the center are observed in the captured image.
Since such chromatic aberration of magnification is represented as blurring of the colors of the captured image and causes deterioration of image quality, it is necessary to correct the chromatic aberration of magnification. In the related art, an imaging apparatus has a function of correcting chromatic aberration of magnification by a signal process on the signal of a captured image. As the first related art, for example, the input image is divided into 8 radial areas, and a radial edge is detected for each divided area. Then, the amount of color deviation of the detected edge part is calculated, and a difference in magnification of a different color image face is calculated for each edge from the aberration amount. The pixel value of a position changed from a process target pixel by chromatic aberration of magnification is calculated on the basis of the difference in magnification with the highest frequency of appearance, and the pixel value is a pixel value of the process target pixel (e.g., see JP-A-2006-20275, FIG. 1).
As the second related art, a difference in magnification in the four directions up, down, left, and right is calculated using the difference in magnification calculated for each of the 8 divided areas. A method of acquiring a shift vector of color deviation for each of the four screens divided in the directions up, down, left, and right is known (e.g., see JP-A-2006-20275, FIG. 1).
As the third related art, a configuration of correction of chromatic aberration of magnification described as follows is known. That is, a movement amount of each pixel position is calculated in advance, and data of such movement amounts are associated with lens parameters and are stored as correction data in an imaging apparatus. At the time of a correction process, a correction amount is acquired for each pixel selected as a process target using the correction data. Then, the pixel value of a position changed from the process target pixel by chromatic aberration of magnification is calculated on the basis of the correction amount, and the pixel value is a pixel value of the process target pixel (e.g., see JP-A-2006-135805, FIG. 5).